CH712075A2 - A yarn monitoring device, a yarn winding machine and an automatic winder. - Google Patents

Abstract

A yarn monitoring device comprises an optical thickness detection section of a yarn and a correction section. The thickness detection section of a yarn is adapted to detect a yarn thickness of a moving yarn. The correction section confirms the yarn thickness detected by the yarn thickness detection section and performs a first correction to correct the yarn thickness when the confirmed yarn thickness satisfies a predetermined increase condition, in a first predetermined period. Furthermore, the correction section confirms the yarn thickness detected by the yarn thickness detection section and performs a second correction to correct the yarn thickness when the confirmed yarn thickness satisfies a predetermined reduction condition, in a second different predetermined period from the first predetermined period.

Description

Description

INTRODUCTION TO THE INVENTION 1. Field of the Invention The present invention relates mainly to a yarn monitoring device suitable for monitoring a moving yarn. 2. Description of the prior art [0002] Conventionally, a yarn winding machine, such as a spinning machine, an automatic winder and the like, includes an optical monitoring device for a yarn suitable for monitoring a yarn that is wound. The yarn monitoring device irradiates a moving yarn with light and receives a transmitted light which has been transmitted through the yarn or a reflected light which has been reflected by the yarn with a light-receiving element such as a photodiode to monitor a thickness of yarn and the like in real time and detect a yarn defect (portion with an anomaly in the quality of the yarn).

[0003] JP 2000-327 226 A and JP 2007-131 974 A disclose this type of optical monitoring device for a yarn.

During the winding of the yarn, a temperature of the yarn monitoring device can be lowered when an air flow is generated as a result of the movement of the yarn, or the temperature of the yarn monitoring device can increase when it is generated. friction heat as a result of yarn movement. A light projection element and a light receiving element are influenced by this temperature variation and, therefore, their properties (amount of light that will be projected, current that will be emitted and similar) change. In this regard, JP 2000-327 226 A and JP 2007-131 974 A disclose a process for correcting an output signal and similar to the light receiving element in consideration of the temperature variation during the movement of the yarn. However, in JP 2000-327 226 A and JP 2007-131 974 A the timing for performing this correction is not described in detail.

BRIEF SUMMARY OF THE INVENTION

[0005] The present invention has been realized in consideration of the above circumstances, and its main objective consists in providing a monitoring device for a yarn, a yarn winding machine and an automatic winder which perform a correction process. of a thickness of a yarn with an appropriate timing in consideration of a temperature change during the movement of the yarn.

[0006] The problems which the present invention intends to solve are described above and the means and effects capable of solving these problems will now be described.

[0007] According to a first aspect of the present invention, a monitoring device is provided for a yarn having the following configuration. Specifically, the yarn monitoring device comprises an optical thickness detection section of yarn and a correction section. The yarn thickness detection section is adapted to detect a yarn thickness of a moving yarn. The correction section performs a first confirmation process comprising a step of confirming the thickness of yarn detected by the yarn thickness detection section, and performing a first correction comprising a step of correcting the yarn thickness when the yarn thickness confirmed in the first confirmation process satisfies a predetermined increase condition, in a first predetermined period of time or length covered by the yarn. Moreover, the correction section performs a second confirmation process comprising a step of confirming the yarn thickness detected by the yarn thickness detection section, and performing a second correction comprising a step of correcting the yarn thickness when the yarn thickness confirmed in the second confirmation process satisfies a predetermined reduction condition, in a second predetermined period of time or length covered by the yarn, different from the first predetermined period.

[0008] Therefore, since the behavior in the variation of the yarn thickness differs between when the yarn thickness has increased and when the yarn thickness is reduced, the period corresponding to each case is set so that 10 yarn thickness can be corrected with an appropriate timing corresponding to the variation of the yarn thickness, while taking into consideration the temperature variation during the movement of the yarn.

[0009] In embodiments of the yarn monitoring device, the first period of time or length traveled is shorter than the second period.

[0010] Therefore, when the yarn thickness has increased, the yarn thickness can change rapidly, and therefore it is necessary that the period be set short to perform the correction frequently. On the other hand, when the yarn thickness is reduced, the yarn thickness changes gradually. However, also the detection value of the yarn thickness detection section (i.e., the detected yarn thickness) gradually changes due to the influence of the temperature variation. Therefore, when the yarn thickness is reduced, it is necessary that the period is set long to distinguish whether the yarn thickness is actually reduced or the yarn thickness seems reduced due to the influence of the temperature variation. When the yarn thickness has increased, the actual yarn thickness varies substantially rapidly, but the detection value of the yarn thickness detection section due to the influence of the temperature variation varies relatively gradually, as described above. Therefore, if the yarn thickness has actually increased or if the yarn thickness seems to have increased due to the influence of the temperature variation, it can be easily distinguished (in a short time). Therefore, the yarn thickness can be corrected with an appropriate timing corresponding to the variation of the yarn thickness.

[0011] In embodiments, the yarn monitoring device described above has the following configuration. Specifically, the monitoring device of a yarn comprises a section for detecting the length of movement of the yarn adapted to detect a length of movement of the yarn which is a length that the yarn has traveled. The correction section, based on the length of movement of the yarn detected by the yarn length detection section, performs the first confirmation process and determines whether the yarn thickness confirmed in the first confirmation process satisfies the predetermined increase condition each time the yarn travels through a first predetermined length, and carries out the second confirmation process and determines whether the yarn thickness confirmed in the second confirmation process satisfies the predetermined reduction condition each time the yarn travels through a second predetermined length.

Therefore, the correction timing is determined based on the length of movement of the yarn, so that the yarn thickness can be corrected more accurately than in the case in which the correction timing is determined based on time.

[0012] In embodiments of the yarn monitoring device described above, the correction section performs the first confirmation process and determines whether the yarn thickness confirmed in the first confirmation process satisfies the predetermined increase condition each time it has elapsed a first predetermined time, and performs the second confirmation process and determines whether the yarn thickness confirmed in the second confirmation process satisfies the predetermined reduction condition each time a second predetermined time has elapsed.

Therefore, the correction timing can be determined without detecting the length of movement of the yarn, so that the process can be simplified.

[0013] In embodiments of the yarn monitoring device described above, the correction section obtains, as the reference thickness of the yarn, a value based on an average of the yarn thicknesses from the start of the movement of the yarn to when the yarn has traveled a predetermined length or when a predetermined time has elapsed, and performs the first correction based on an increased amount of yarn thickness starting from the reference thickness of the yarn, and performs the second correction based on a reduced quantity of thickness of yarn starting from the reference thickness of the yarn.

Therefore, it is assumed that the influence of the temperature variation is small for a predetermined time from the start of the yarn movement and, therefore, the influence of the temperature variation and the like can be accurately estimated taking as a reference the average (thickness of yarn reference) of the yarn thicknesses acquired during this time. Therefore, the yarn thickness can be more accurately corrected.

[0014] Furthermore, in embodiments of the yarn monitoring device described above, the correction section performs the first correction based on a correction amount obtained by adding a first predetermined fixed value, defined in advance for each first period, to an initial adjustment value defined before the yarn movement starts, and performs the second correction based on a correction quantity obtained by subtracting a second predetermined fixed value defined in advance for each second period from the initial adjustment value.

[0015] In embodiments of the yarn monitoring device described above, the first correction is performed when a thickness of yarn in a time instant of termination of a first current period confirmed in the first confirmation process is increased by a predetermined quantity to starting from a yarn thickness in a temporal instant of termination of a first preceding period, and the second correction is preferably carried out when a yarn thickness of a second current period confirmed in the second confirmation process is continuously reduced.

[0016] In embodiments of the yarn monitoring device described above, the correction section calculates an average of yarn thicknesses in a predetermined length or a predetermined previous time, and performs the first correction to correct the yarn thickness when the average thickness of the yarn in the instant in time of termination of the first current period satisfies the predetermined increase condition.

[0017] According to a second aspect of the invention, a machine for winding a yarn having the following configuration is provided. Specifically, the yarn winding machine comprises a winding section, a yarn thickness detection section and a correction section. The winding section is adapted to wind a yarn to form a cone. The yarn thickness detection section is adapted to detect a yarn thickness of a moving yarn. The correction section performs a first confirmation process comprising a step of confirming the thickness of yarn detected by the yarn thickness detection section, and performing a first correction comprising a step of correcting the yarn thickness when the yarn thickness confirmed in the first confirmation process satisfies a predetermined increase condition, in a first predetermined period of time or length covered by the yarn, and performs a second confirmation process comprising a step of confirming the yarn thickness detected by the yarn thickness detection section , and performs a second correction comprising a step of correcting the yarn thickness when the yarn thickness confirmed in the second confirmation process satisfies a predetermined reduction condition, in a second predetermined period of time or length traveled by the yarn, different from the first predetermined period.

[0018] Therefore, since the behavior in the variation of the yarn thickness differs between when the yarn thickness is increased and when the yarn thickness is reduced, the period corresponding to each case is set so that 10 yarn thickness can be corrected with an appropriate timing corresponding to the change in yarn thickness.

[0019] In embodiments, an automatic winder acting as the yarn winding machine described above has the following configuration. Specifically, the automatic winder comprises a section for detecting the length of movement of the yarn suitable for detecting a length of movement of the yarn which is a length that the yarn has traveled. The winding section wraps the yarn while varying a winding speed, at least temporarily. The correction section performs the first confirmation process and determines whether the yarn thickness confirmed in the first confirmation process satisfies the predetermined increase condition each time the yarn travels through a first predetermined length, and performs the second confirmation process and determines whether the yarn thickness confirmed in the second confirmation process satisfies the predetermined reduction condition each time the yarn runs through a second predetermined length.

[0020] Consequently, even with the automatic winder which wraps the yarn while the winding speed varies, the thickness of yarn can be corrected with an appropriate timing by performing the correction based on the length of movement of the yarn.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]

Fig. 1 is a front view illustrating a general configuration of an automatic winder comprising a yarn monitoring device according to an embodiment of the present invention; fig. 2 is a side view of a winding unit comprising the yarn monitoring device; fig. 3 is a block diagram illustrating an electrical configuration of the monitoring device for a wire; fig. 4 is a graph illustrating a relation of a length of movement of the yarn and a voltage of an electrical signal (thickness of yarn); fig. 5 is a graph illustrating a relation of the length of movement of the yarn, the thickness of yarn and a quantity of correction; fig. 6 is a flow chart illustrating a first half of a yarn thickness correction process in consideration of a temperature change and the like during the movement of the yarn; and fig. 7 is a flow chart illustrating a second half of the yarn thickness correction process in consideration of the temperature variation and the like during the movement of the yarn.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0022] In the following, an embodiment of the present invention will be described with reference to the drawings.

[0023] As shown in fig. 1, an automatic winder (yarn winding machine) 1 comprises, as main components, a plurality of winding units (yarn winding units) 10 arranged side by side, and a machine control section 11 arranged at an end in a direction in which the winding units 10 are arranged.

[0024] The machine control section 11 comprises a display device 12 capable of displaying information associated with each winding unit 10, an instruction entry section 13 suitable for insertion by an operator of various types of instructions in connection with the control section of machine 11 and the like. The operator of the automatic winder 1 can verify various types of visualizations displayed on the display device 12 and can also suitably use the instruction input section 13 to collectively manage the plurality of winding units 10 with the machine control section 11 .

[0025] Each wrapping unit 10 illustrated in figs. 1 and 2 is configured to unwind a yarn from a yarn supply reel 20 and rewind the yarn around a winding bobbin 22. The winding bobbin 22 with a yarn 21 wrapped around it is referred to as a bobbin 23. In the description following, «upstream in the direction of movement of the yarn» and «downstream in the direction of movement of the yarn» indicate upstream and downstream respectively by looking in the direction of movement of the yarn 21.

[0026] As shown in fig. 2, the winding unit 10 comprises a main body frame 24, a yarn feeding section 25 and a winding section 26 as main components.

[0027] The main body frame 24 is arranged at one side of the winding unit 10. Most of the components of the winding unit 10 are supported directly or indirectly by the main body frame 24.

[0028] The yarn feeding section 25 is configured to be able to support the yarn supply bobbin 20, adapted to feed the yarn 21, in a substantially vertical state. The winding section 26 comprises a support 28 and a winding cylinder 29.

[0029] The support 28 rotatably supports the winding coil 22. Furthermore, the support is configured to allow a perimeter surface of the support winding coil 22 to come into contact with a perimeter surface of the winding cylinder 29. The winding cylinder 29 is arranged to face the winding coil 22 and is configured to be rotatably actuated by a motor driving the winding cylinder (not shown). A translation groove (not shown) having a reciprocal spiral shape to translate the yarn 21 wrapped around the winding bobbin 22 is formed on the outer perimeter surface of the winding cylinder 29.

[0030] The winding coil 22 is driven and rotated by the rotatable actuation of the winding cylinder 29 with the outer perimetric surface of the winding coil 22 in contact with the winding cylinder 29. Therefore, the yarn 21 unwound from the supply bobbin of the yarn 20 can be wound around the winding bobbin 22 while it is translated by the translation groove. The component capable of translating the yarn 21 is not limited to the winding cylinder 29 and, for example, instead of the winding cylinder 29, it is possible to adopt an arm-shifting device capable of guiding the yarn 21 with a translation guide operated alternately with a predetermined translation width. When the arm-shifting device is adopted, the winding coil 22 is preferably rotatably driven directly.

[0031] Each wrapping unit 10 comprises a unit control section 30. The unit control section 30 is configured with hardware, such as CPU, ROM and RAM, and software, such as a control program stored in ROM or RAM . With the cooperation of hardware and software, each component of the winding unit 10 is controlled. The unit control section 30 of each winding unit 10 is configured to be in communication with the machine control section 11. Thus, the operation of each winding unit 10 can be intensively managed by the machine control section. 11.

[0032] The winding unit 10 has a configuration in which an unwinding facilitating device 31, a tension application device 32, a yarn junction device 33 and a yarn monitoring device 6 are arranged in this order from the upstream position in the direction of movement of the yarn on a path of movement of the yarn between the feeding section of the yarn 25 and the winding section 26.

[0033] The unwinding facilitating device 31 comprises an adjustment element 35 able to come into contact with a portion (bale) prominent towards the outer side when the yarn 21 unwound from the spool for feeding the yarn 20 is made to oscillate by a centrifugal force . The contact of the adjustment element 35 with the bale prevents the yarn 21 from being oscillated in excess and keeps the bale at a predetermined size, thus allowing the unwinding of the yarn 21 from the yarn supply bobbin 20 to be performed with a preset voltage.

[0034] The tension application device 32 is able to apply a predetermined voltage on the moving yarn 21. The tension application device 32 of the present embodiment can be a comb-type tension application device in which Movable comb are arranged with respect to fixed comb teeth. The tension application device 32 applies an appropriate tension on the yarn 21 by passing the yarn 21 while it is folded between the comb teeth in a engaged state. As a voltage application device 32 it is possible to adopt a voltage application device different from the comb type, for example a disc type tension application device.

[0035] The yarn junction device 33 is configured to join (yarn splicing operation) a yarn (lower yarn) from the yarn spool 20 and a yarn (upper yarn) from the winding bobbin 22 when the yarn 21 they are disconnected between the yarn supplying bobbin 20 and the winding bobbin 22, such as when the yarn is cut with a cutting device (cutter) 16, which will be described later. The configuration of the junction device of the yarn 33 is not particularly limited, but a pneumatic splicer can be adopted which twists the ends of the yarn with a swirling air flow generated by compressed air, or a mechanical knotter and the like, A upper yarn suction tube 44 sucks and captures the end of the yarn from the winding bobbin 22 and guides the end of the yarn towards the yarn joining device 33. A lower yarn suction tube 45 sucks and captures the end of the yarn from the yarn supply reel 20 and guides the end of the yarn towards the yarn joining device 33.

[0036] The yarn monitoring device 6 monitors the state (thickness, mixture of foreign substances such as colored yarn, polypropylene and the like) of the yarn in motion 21 and detects a yarn defect contained in yarn 21. The yarn monitoring device 6 can detect a speed of yarn movement of the yarn in movement 21. The yarn monitoring device 6 further comprises the cutter 16 adapted to cut the yarn 21 when the yarn monitoring device 6 detects the yarn defect. The detailed configuration of the yarn monitoring device 6 will be described later.

[0037] Now, a brief description of an operation relating to when the yarn defect and the like is detected by the yarn monitoring device 6 will be provided with reference to fig. 2.

[0038] When the yarn defect and the like is detected in yarn monitoring, the yarn monitoring device 6 activates the cutter 16 to cut the yarn 21, and also transmits a yarn defect detection signal to the control section of unit 30. The yarn 21 positioned downstream of the cutting area is wound once in a cone 23. The yarn 21 wound in the cone 23 in this case includes a yarn defect portion and the like detected by the yarn monitoring device 6 After receiving the yarn defect detection signal, the unit control section 30 stops the winding of the yarn 21 by the winding section 26.

[0039] The lower yarn suction tube 45 sucks and captures the end of the yarn fed by the yarn supplying bobbin 20 and guides the end of the yarn towards the yarn joining device 33. Before or after this, the upper yarn suction tube 44 sucks and captures the end of the yarn wound in the bobbin 23 and guides the end of the yarn towards the junction device of the yarn 33. In this case, the portion of the yarn defect is similar wound in the bobbin 23 is sucked in and pulled out of the upper yarn suction tube 44.

[0040] The yarn junction device 33 joins the ends of the yarn guided by the upper yarn suction tube 44 and the lower yarn suction tube 45. Therefore, after the portion which includes the yarn defect and the like has been removed, the yarn 21 cut by the cutter 16 is connected again.

[0041] After the yarn splicing operation has been completed by means of the yarn splicing device 33, the unit control section 30 takes up the winding of the yarn 21 by means of the winding section 26. According to the operations of which above, the yarn and similar defect detected by the yarn monitoring device 6 can be removed, and the winding of the yarn 21 in the cone 23 can be resumed.

[0042] Furthermore, in the present embodiment, the unit control section 30 performs a noise control (periodic check) to prevent the generation of a ribbed winding (a state in which the yarn 21 is concentrated in an area and wrapped in an overlapping manner). Specifically, the unit control section 30 controls the drive motor of the winding cylinder (not shown) and periodically changes the speed of rotation of the winding cylinder 29 to make the bobbin 23 and the winding cylinder 29 slide, thus changing the winding speed. Therefore, in the present embodiment, the speed of yarn movement of the yarn 21 is not constant. Moreover, since the bobbin 23 and the winding cylinder 29 slide, an accurate speed of yarn movement cannot be detected even if the speed of rotation of the winding cylinder 29 is used. Furthermore, the speed of movement of the yarn is not constant even if Noise control is not performed. For example, when a conical cone is formed, the speed of movement of the yarn varies considerably depending on whether the yarn is wound around the long diameter side of the cone or the short diameter side of the cone and, consequently, it is difficult detecting an accurate yarn movement speed exclusively based on the speed of rotation of the winding cylinder 29.

[0043] Subsequently, a description of the details of the yarn monitoring device 6, in particular of the electrical configuration by referring to fig. 3. Fig. 3 is a block diagram illustrating an electrical configuration of the yarn monitoring device 6.

[0044] As shown in fig. 3, the yarn monitoring device 6 comprises an optical sensor unit (yarn thickness sensing section) 50 and a yarn monitoring control section 60.

The sensor unit 50 can measure the state of the yarn 21. The sensor unit 50 comprises a drive circuit 51, a light projection section 52, a light receiving section 53, an amplifier 54, a high-pass filter 55 and an amplification circuit 56. The cutter 16 is fixed to a housing of the sensor unit 50. In the present embodiment, a total of two groups of light projection section 52 and receiving section are provided of the light 53, in which each group is arranged in a different position on the path of movement of the yarn. In other words, the projection section of the light 52 comprises a first light projection section arranged upstream of the yarn movement path and a second light projection section arranged downstream of the yarn movement path. The light receiving section 53 comprises a first light receiving section arranged upstream of the yarn movement path and a second light receiving section disposed downstream of the yarn movement path.

[0046] The projection section of the light 52 comprises a light-emitting element configured by means of a light-emitting diode (LED). The projection section of the light 52 radiates light a space (a slit-shaped recess of Fig. 3), through which the yarn 21 slides, with the light in an amount corresponding to an actuation voltage input from the driving circuit 51. The driving voltage generated by the drive circuit 51 is determined based on an electrical signal input from the yarn monitoring section 60.

[0047] The light receiving section 53 is arranged on an opposite side of the light projection section 52 with a yarn path between them. The light receiving section 53 comprises a light receiving element configured by means of a photodiode and the like. The light receiving section 53 receives the transmitted light of the radiated light from the projection section of the light 52 on the yarn 21, and emits the electrical signal (output voltage or output current) corresponding to the amount of light reception. The electrical signal varies according to the shape (shape of the cross section) of the yarn 21 present in a detection region 70. The transmitted light indicated in the present is the light which has reached the light receiving section 53 when the light emitted by the section Projection of the light 52 is partially shielded by the presence of the yarn 21. In other words, the transmitted light is the light that has passed through the yarn 21. The sensing region 70 is a region, in the slot-shaped recess, struck by the light from the projection section of the light 52, and is a region in which the yarn 21 can be detected depending on the amount of light reception of the light receiving section 53.

[0048] The electrical signal emitted by the light receiving section 53 is amplified by the amplifier 54 and is also subject to an inversion process. Therefore, a conversion is made in such a way that the electrical signal emitted by the amplifier 54 is reduced as the amount of light reception of the light receiving section 53 increases (that is, the more the yarn 21 is tightened) . A signal of a high frequency predetermined in the electrical signal emitted by the amplifier 54 is extracted in the high-pass filter 55, and the electrical signal is again amplified by the amplification circuit 56. The sensor unit 50 detects the thickness of yarn 21 in this way. The sensor unit 50 sends the electrical signal indicating the result of the detection of the yarn thickness to the yarn monitoring section 60.

[0049] The yarn monitoring section 60 for monitoring includes a section for detecting the length of movement of the yarn 61 and a correction section 62. The detection section for the movement length of the yarn 61 detects the length (movement length of the yarn). yarn) of the yarn 21 which slides through the sensing region 70 obtaining, starting from the irregularity of the thickness and the like of the yarn 21, to what extent the electric signal emitted by the light receiving section 53 is delayed with respect to the electric signal emitted by the another light receiving section 53. The correction section 62 corrects the yarn thickness in consideration of the variation of the properties and the like of the projection section of the light 52 and of the light receiving section 53 caused by the temperature variation (this will be described in detail later). The sensor unit 50 and the monitoring section for monitoring the yarn 60 are arranged for each automatic winder 1, so that the correction of the yarn thickness is performed for each automatic winder 1.

[0050] The cutter 16 described above is arranged near the sensing region 70 formed in the housing of the sensor unit 50. The cutter 16 comprises a cutting blade (not shown) operated, for example, by means of a solenoid. The cutter 16 is electrically connected to the monitoring control section of the yarn 60 and is capable of cutting the yarn 21 based on a cutting signal emitted by the yarn monitoring section 60.

[0051] Next, a description of the correction made by the correction section 62 of the yarn monitoring device 6 will be provided with reference to the figs. from 4 to 7.

[0052] In the graph of fig. 4, a horizontal axis indicates a length of movement of the yarn, and a vertical axis indicates a tension (i.e., the thickness of yarn) of an electrical signal input from the sensor unit 50 into the yarn monitoring section 60 Below, the graph will be described by time series. At a time moment in which the length of movement of the yarn is at one left end, the winding of the yarn 21 has not yet begun, and the yarn 21 is not present in the sensing region 70. Thus, the tension of when the length of yarn movement is in the left end corresponds to a tension (initial adjustment value of fig. 5) emitted regardless of the presence / absence of the yarn 21.

[0053] Subsequently, the upper yarn suction tube 44 and the lower yarn suction tube 45 guide the ends of the yarn towards the junction device of the yarn 33 to insert the yarn 21 in the detection region 70. In the graph of the fig . 4, after the yarn 21 has been inserted into the sensing region 70, the yarn 21 is shielded from the light and, therefore, the voltage of the electrical signal becomes high. Since the yarn 21 is not moving in this stage, the yarn thickness does not change and, consequently, the voltage of the electrical signal is constant.

[0054] Subsequently, the junction device of the yarn 33 performs the yarn splicing operation, after which the movement of the yarn 21 is started. In the graph of fig. 4, after the start of the movement of the yarn 21, the voltage of the electrical signal varies according to the irregularity of the thickness and the similarity of the yarn 21.

[0055] The correction section 62 obtains a "reference thickness of the yarn", which is a value obtained by subtracting the initial adjustment value described above from an average of the yarn thicknesses (electrical signal voltages) starting from the start of the movement of the yarn 21 until the yarn 21 has traveled a predetermined length (in the present embodiment, 25 m) (see Fig. 5). The reference thickness of the yarn can be obtained starting from the average thickness of the yarn starting from the start of the movement of the yarn 21 until a predetermined time has elapsed. The predetermined length and the predetermined time in obtaining the reference thickness of the yarn can always be constant, or a value corresponding to the winding conditions (type, winding speed and the like of yarn 21) can be used.

[0056] After the reference thickness of the yarn has been obtained, the correction section 62 obtains (calculates) an average thickness of yarn. The average thickness of yarn is the average (moving average) of the yarn thicknesses of the yarn 21 in a predetermined length or in a predetermined previous time. The average thickness of yarn is a value comprising an adjustment value, contrary to the reference thickness of the yarn. In the present embodiment, the average of the yarn thicknesses of the previous 25 m, which is equal to the reference thickness of the yarn, is assumed as average yarn thickness. The predetermined length or the predetermined time in calculating the reference thickness of the yarn is preferably the same but may be different from the predetermined length or from the predetermined time in calculating the average yarn thickness. Therefore, at the start of the calculation of the average yarn thickness (LO of Fig. 4), the (yarn reference thickness + initial adjustment value) and the average yarn thickness are equal. In the present embodiment, the correction section 62 updates the average thickness of yarn each time the yarn 21 travels 5 m.

[0057] The correction section 62 starts correcting the yarn thickness after starting the calculation of the average yarn thickness. Below, a description of the correction made by the correction section 62 will be provided with reference to figs. 6 and 7. Figs. 6 and 7 are flow charts illustrating a process for correcting the thickness of yarn in consideration of the variation in temperature and the like during the movement of the yarn.

[0058] Firstly, the correction section 62 acquires the length of movement of the yarn rewashed by the detection section of the movement length of the yarn 61 (S101). Subsequently, the correction section 62 waits until the movement length of the acquired yarn is a whole multiple of a first predetermined length (5 m) (S102). The first predetermined length is a period for performing a correction of the yarn thickness (hereinafter referred to as "first correction") when the detected yarn thickness has increased (including the case in which the voltage of the electrical signal is increased for the variation of temperature). In other words, the correction section 62 determines whether to carry out the first correction each time the yarn 21 runs through the first predetermined length. Moreover, the correction section 62 performs a confirmation process (first confirmation process) to confirm the yarn thickness and determines whether the yarn thickness confirmed in the first confirmation process satisfies a predetermined increase condition each time the yarn 21 runs the first predetermined length. The period of the first correction is not limited to the length of movement of the yarn, and can be performed at any predetermined time (first predetermined time).

[0059] When the length of movement of the yarn becomes a whole multiple of the first predetermined length (5, 10, 15 m and so on), the correction section 62 obtains the average thickness of yarn as described above, and determines whether the average thickness of yarn is greater than the average yarn thickness of a previous period (ie, 5 m before) (S103). When the average yarn thickness of a previous period does not exist or is zero (immediately after the start of the movement of yarn 21, and the like), the average thickness of yarn obtained in this time is stored and the process is terminated.

[0060] When the average yarn thickness obtained in this time is greater than the average yarn thickness of a previous period, the correction section 62 activates a first correction execution indicator (S104) and passes to the subsequent process. When the average thickness of yarn obtained in this time is less than or equal to the average yarn thickness of a previous period, the correction section 62 passes to the subsequent process without activating the first correction indicator.

[0061] Subsequently, the correction section 62 determines whether the movement length of the acquired yarn has reached a second predetermined length (35 m) (S105). The second predetermined length is a period for carrying out a correction of the yarn thickness (hereinafter referred to as "second correction") when the yarn thickness is reduced (including the case in which the voltage of the electrical signal is reduced due to the variation of temperature). In other words, the correction section 62 determines whether to carry out the second correction each time the yarn 21 runs through the second predetermined length. Furthermore, the correction section 62 performs a confirmation process (according to the confirmation process) to confirm the yarn thickness. and determines whether the yarn thickness confirmed in the second confirmation process satisfies a predetermined reduction condition each time the yarn 21 passes through the second predetermined length. The period of the second correction is not limited to the length of movement of the yarn, and can be performed at any predetermined time (second predetermined time).

[0062] When the length of movement of the yarn has reached (exceeded) the second predetermined length, the correction section 62 determines whether the average thickness of yarn obtained in this time is less than the average yarn thickness of a previous period (ie say, 35 m before) (S106). When the average yarn thickness obtained in this time is less than the average yarn thickness of a previous period, the correction section 62 activates a second correction execution indicator (S107) and passes to the subsequent process. When the average thickness of yarn obtained in this time is greater than the average yarn thickness of a previous period, the correction section 62 passes to the subsequent process without activating the second correction indicator. In steps S106 and S107 it can be determined whether the average yarn thickness of the second current period is continuously reduced, and the second correction execution indicator can be activated if the average yarn thickness is reduced continuously.

[0063] When the determination of the step S106 is performed, the correction section 62 resets the value of the length of movement of the yarn (S108). As a result, the length of movement of the yarn is counted again starting from zero.

[0064] Next, the correction section 62 determines whether the first correction execution indicator or the second correction execution indicator is activated (S109 in Fig. 7). If neither of the two correction execution indicators is activated, the correction section 62 ends the process. When one of the correction execution indicators is activated, the correction section 62 acquires the reference thickness of the yarn obtained at the start of the movement of the yarn 21 (S110).

[0065] Next, the correction section 62 calculates a new correction amount (Siles). Specifically, as shown in fig. 5, a correction adjustment value is calculated by subtracting the reference thickness of the yarn from the average thickness of yarn obtained at this time. To describe this calculation, the reference thickness of the yarn indicates more or less clearly the thickness of the yarn since the reference thickness of the yarn is obtained in a situation in which the influence and similar of the temperature variation is low. Therefore, the adjustment value (correction adjustment value) which takes into account the influence of the current temperature variation, of the variation of the fiber quantity of the yarn 21 or similar, can be calculated by subtracting the reference thickness of the yarn from the thickness average of yarn. Moreover, the fluctuation amount (correction amount) of the voltage due to the influence of the temperature variation, of the variation of the fiber quantity of the yarn 21 or similar, is obtained by subtracting the initial adjustment value from the correction adjustment value. The correction quantum is positive in the example shown in fig. 5, but may be negative depending on the situation.

[0066] After the calculation described above, the correction section 62 determines whether an absolute value of the correction amount is greater than a predetermined threshold value (S112). When the absolute value of the correction amount is greater than the predetermined threshold value, the correction section 62 determines that the amount of variation of the detection value due to the influence of the temperature change increases and the influence on the gain becomes too great and therefore, the cutter 16 is activated to cut the yarn 21 (S113).

[0067] On the other hand, when the absolute value of the correction quantity is less than or equal to the predetermined threshold value, the correction section 62 corrects the yarn thickness based on the calculated correction amount (S114). Therefore, when the first correction execution indicator is activated, the first correction is performed. For example, when the movement length of the yarn of FIG. 5 is between 0 m and 35 m (first count), the average thickness of yarn has increased gradually with respect to 5 m before and, therefore, the correction quantity is correct at each first predetermined length (every 5 m). When the second correction execution indicator is activated, the second correction is performed. For example, when the movement length of the yarn of FIG. 5 is 35 m (second and third count), the average yarn thickness is reduced compared to the average yarn thickness of 35 m before and, therefore, the correction quantity is correct. When both the first correction execution indicator and the second correction execution indicator are activated, one of the previously defined corrections is performed.

[0068] Therefore, in the present embodiment, the period for determining whether the correction is necessary differs between when the increased quantity of the detected yarn thickness is greater than or equal to a predetermined quantity (when the first correction is performed) and when the quantity reduced in the detected yarn thickness is greater than or equal to a predetermined amount (when the second correction is performed). This is due to the following reasons. That is to say, a case in which the yarn thickness is increased comprises a situation in which a cotton dust is entangled around the yarn 21 in the stage of generating the yarn 21, and the like, and the yarn thickness increases rapidly in this situation . On the other hand, when the yarn thickness increases due to the influence of the temperature variation, the detection value of the sensor unit 50 (ie, the thickness of the yarn detected) varies gradually. Therefore, it is possible to distinguish in a short time if the yarn thickness has actually increased or the yarn thickness seems increased due to the influence of the temperature variation. Therefore, it can be frequently determined (shorter period) if the yarn thickness is increased. A case in which the yarn thickness is reduced comprises a situation in which fibers contained in the yarn 21 in the step of generating the yarn 21 are gradually removed, and the like, and the thickness of yarn is gradually reduced in this situation. On the other hand, when the yarn thickness is reduced due to the influence of the temperature variation, the detection value of the sensor unit 50 (ie, the thickness of the yarn detected) varies gradually. Therefore, when the yarn thickness is reduced, it is necessary to lengthen the period to distinguish if the yarn thickness is actually reduced or if the yarn thickness seems reduced due to the influence of the temperature variation. In view of the above, the period of the first correction is shortened with respect to the period of the second correction in the present embodiment.

[0069] When the yarn is disconnected (breaking of the yarn or yarn cut by the cutter) after the start of the correction, as shown in fig. 4, the initial adjustment value is correct. Moreover, the reference thickness of the yarn can be calculated by means of the yarn 21 which runs along a length (in the present embodiment, 25 m) corresponding to the calculation of the reference thickness of the yarn from the start of the movement of the yarn 21. Therefore, the correction of the yarn thickness is again taken up with this timing.

[0070] As described above, the yarn monitoring device 6 of the present embodiment comprises the optical sensor unit 50 and the correction section 62. The sensor unit 50 detects the yarn thickness of the moving yarn 21. The correction section 62 performs a first correction to correct the yarn thickness in a predetermined period (when a correction is required) based on the increased amount of yarn thickness detected by the sensor unit 50, and a second correction to correct the yarn yarn thickness in a different period than the first correction (when a correction is required) based on the reduced amount of yarn thickness detected by the sensor unit 50.

[0071] Therefore, since the behavior in the variation of the thickness of yarn differs between when the thickness of yarn is increased and when the thickness of yarn is reduced, the period corresponding to each case is set so that the thickness of yarn can be corrected with an appropriate timing corresponding to the variation of the yarn thickness, while taking into consideration the temperature variation during the movement of the yarn.

[0072] The yarn monitoring device 6 of the present embodiment comprises the section for detecting the length of movement of the yarn 61 suitable for detecting the length of movement of the yarn which is the length that the yarn 21 has traveled. The correction section 21 determines whether to carry out the first correction each time the yarn 21 runs through the first predetermined length, and determines whether to perform the second correction each time the yarn 21 travels through the second predetermined length based on the length of movement of the detected yarn from the section for detecting the length of movement of the yarn 61.

[0073] Therefore, the correction timing is determined based on the length of movement of the yarn, so that the yarn thickness can be more accurately corrected with respect to the case in which the correction timing is determined based on the time .

[0074] Furthermore, in the yarn monitoring device 6 of the present embodiment, the correction section 62 obtains as a reference thickness of the yarn a value based on the average thickness of the yarn starting from the start of the movement of the yarn 21 up to when the yarn 21 has traveled a predetermined length, and performs the first correction or the second correction on the basis of the increased quantity or the reduced quantity with respect to the reference thickness of the yarn.

[0075] Therefore, it is assumed that the influence of the temperature variation is low for a predetermined time from the start of the movement of the yarn 21, so that the influence of the temperature variation and the like can be accurately estimated taking as a reference the average thickness of the yarn (reference thickness of the yarn) acquired during that time. Therefore, the yarn thickness can be more accurately corrected.

[0076] Furthermore, in the present embodiment, the winding section 26 wraps the yarn 21 while varying at the same time the winding speed at least temporarily to perform the noise control. The correction section 62 determines whether to carry out the first correction each time the yarn 21 travels through the first predetermined length, and determines whether to perform the second correction each time the yarn 21 runs through the second predetermined length based on the length of movement of the detected yarn from the section for detecting the length of movement of the yarn 61.

[0077] Consequently, even with the automatic winder which wraps the yarn 21 while the winding speed varies, the yarn thickness can be corrected with an appropriate timing by performing the correction based on the length of movement of the yarn.

[0078] The preferred embodiment of the present invention has been described above, but the configuration described above can be modified as follows.

[0079] In the embodiment described above, the yarn monitoring device 6 has the voltage reversed by the amplification circuit 56 and, consequently, the yarn thickness increases as the voltage of the electrical signal entered in the control section increases. yarn monitoring 60. However, it is also possible to adopt a configuration in which the voltage is not reversed. In this case, the correction of when the voltage of the electrical signal entered into the monitoring control section of the yarn 60 decreases (i.e., when the yarn thickness is increased) corresponds to the first correction.

[0080] In the embodiment described above, the yarn monitoring device 6 has a configuration in which the cutter 16 is incorporated. However, the present invention is not limited to this and the cutter can be arranged outside the monitoring device. of the yarn 6, and the cutter can be controlled by the unit control section 30. In this case, the yarn monitoring section 60 sends the yarn cutting signal to the unit control section 30, and the section The unit 30 controls the cutter based on the yarn cutting signal. Furthermore, the yarn monitoring device 6 is configured to cut the yarn 21 with the cutter 16 and remove the yarn defect when the yarn defect is detected, but the yarn monitoring device of the present invention can be a device that simply monitors the status of yarn 21 without cutting yarn 21 with the cutter.

[0081] In the embodiment described above, the yarn monitoring device 6 comprises a section for detecting the thickness of yarn and the section for detecting the length of movement of the yarn, but each between the section for detecting the thickness of the yarn and the detection section of the yarn movement length can be realized with different devices. When the yarn monitoring device 6 does not include the section for detecting the length of movement of the yarn, and the length of movement of the yarn (speed of movement of the yarn 21) is detected with a device different from the yarn monitoring device 6, the yarn monitoring device 6 can have a configuration that includes a group of light projection section and light receiving section.

[0082] The yarn monitoring device 6 is not limited to the configuration in which two groups of light projection section and light projection section are arranged in total, in which each group is arranged in different positions on the path of movement of the yarn. As described above, it is possible to arrange only one group of light projection section and light receiving section. Regardless of whether only a group of light projection section and light receiving section is arranged or that multiple groups are arranged, the number of light projection sections and the number of light receiving sections arranged in a non-group it is limited to one each. For example, in one group, one or a plurality of light projection sections and one or a plurality of light receiving sections may be arranged. Specifically, a first group arranged upstream may comprise a light projection section and three light receiving sections, and a second downstream group may comprise two light projection sections and two light receiving sections.

[0083] In the embodiment described above, it is assumed that the predetermined length to obtain the reference thickness of the yarn is 25 m, that the period of the first correction is 5 m and that the period of the second correction is 35 m, but these values are arbitrary and can be changed appropriately (for example, they can be double

Claims (10)

or three times the aforementioned values). Moreover, in the embodiment described above, it is assumed that the predetermined length to obtain the reference thickness of the yarn and the period of the second correction are integer multiples of the period of the first correction, but may not be integer multiples. [0084] The process described in the flowcharts described above is an example and it is possible to realize additions, variations, order changes, eliminations and the like of the flow within the scope without departing from the present invention. [0085] In the embodiment described above, the period of the first correction is shorter than the period of the second correction but the period of the first correction can be longer than the period of the second correction according to the winding conditions and the like. [0086] In the embodiment described above, the calculation is performed by introducing values such as the reference thickness of the yarn, the average thickness of yarn, the initial adjustment value, the correction adjustment value and the correction value, but this calculation is an example and can be changed appropriately. For example, the calculation can be performed assuming the value obtained by adding the initial adjustment value to the reference thickness of the yarn of the embodiment described above as «reference thickness of the yarn». [0087] Furthermore, in the embodiment described above, the correction amount is calculated starting from the amount of variation when the electrical signal is changed by the temperature variation, as shown in Siles in the flow diagram of Fig. 7. However, for example, instead of calculating the correction amount starting from the variation amount, a predetermined fixed value can be added / subtracted with respect to the previous correction adjustment value to correct the yarn thickness when it is determined that the correction is required for each correction period. As a result, the correction can be performed more easily. [0088] More precisely, a first predetermined fixed value is added each first period to the initial adjustment value to obtain the correction adjustment value (correction amount), and the first correction is performed based on the obtained correction amount. Furthermore, a second predetermined fixed value is subtracted every second period from the initial adjustment value to obtain the correction adjustment value (correction amount), and the second correction is performed based on the obtained correction amount. For example, describing this with reference to fig. 5, in the time instant in which the length of movement of the yarn is 5 m of the first period, the first fixed value is added to the initial adjustment value to obtain the correction adjustment value to perform the first correction. In the time instant in which the yarn movement length is 10 m of the second period, the first fixed value is further added to the previous correction adjustment value (value obtained by adding the first fixed value to the initial adjustment value) to obtain the amount of correction to perform the first correction. [0089] As described above, the initial adjustment value is defined when the yarn 21 is not present in the detection region 70 before the start of the movement of the yarn 21. The predetermined fixed value is preferably set to different values for when the yarn 21 becomes thick and when the yarn 21 becomes thin, but can be set to the same value. For the predetermined fixed value, a numerical value that allows the apparent variation of the yarn thickness and the effective variation of the yarn thickness for the thermal drift to be distinguished in a distinct way can be experimentally set (by repeated experiments) previously. [0090] At least a part of the process performed by the yarn monitoring section 60 (for example, the correction performed by the correction section 62) can be performed by the unit control section 30 or the machine control section 11. [0091] The configuration of the present invention is not limited to the automatic winder and can be applied to other machines for winding a yarn, such as for example a rewinding machine, a spinning machine (for example, a pneumatic spinning machine, an open-end spinning machine) and so on. claims 1. A yarn monitoring device (6) characterized by comprising: an optical thickness sensing section of yarn (50) adapted to detect a yarn thickness of a moving yarn (21); and a correction section (62) adapted to carry out a correction of the yarn thickness, in which the correction section is configured to perform a first confirmation process comprising a step of confirming the thickness of yarn detected by the thickness detection section of yarn, and perform a first correction comprising a step of correcting the yarn thickness when the yarn thickness confirmed in the first confirmation process satisfies a predetermined increase condition, in a first predetermined period of time or length covered by the yarn, and perform a second confirmation process comprising a step of confirming the thickness of yarn detected by the yarn thickness detection section, and performing a second correction comprising a step of correcting the yarn thickness when the yarn thickness confirmed in the second confirmation process satisfies a predetermined reduction condition, in a second period predict of time or length covered by the yarn, said second predetermined period being different from said first predetermined period. 2. A yarn monitoring device according to claim 1, characterized in that the first period is shorter than the second period. 3. A yarn monitoring device according to claim 1 or 2, wherein said first period and said second period are lengths covered by the yarn, characterized in that it further comprises: a section for detecting the length of movement of the yarn (61) adapted to detecting a length of movement of the yarn which is a length that the yarn has traversed, in which the correction section is configured for: based on the length of movement of the yarn detected by the detection section of the length of movement of the yarn, performing the first confirmation process and determining whether the yarn thickness confirmed in the first confirmation process satisfies the predetermined increase condition each time the yarn travels through a first predetermined length, and execute the second confirmation process and determine whether the yarn thickness confirmed in the second Confirmation process meets the predetermined reduction condition each time the yarn per runs a second predetermined length. 4. A yarn monitoring device according to claim 1 or 2, wherein said first period and said second period are time periods, characterized in that the correction section is configured to: execute the first confirmation process and determine whether the yarn thickness confirmed in the first confirmation process satisfies the predetermined increase condition every time a predetermined first time has elapsed, and execute the second confirmation process and determine whether the yarn thickness confirmed in the second confirmation process satisfies the condition of predetermined reduction each time a second pre-terminated time has elapsed. 5. A yarn monitoring device according to any of the claims from 1 to 4, characterized in that the correction section is configured to obtain, as a reference yarn thickness, a value based on an average of yarn thicknesses starting from from the start of the yarn movement until the yarn has traveled a predetermined length or until a predetermined time has elapsed, perform the first correction based on an increased amount of yarn thickness with respect to the yarn reference thickness, and performing the second correction based on a reduced amount of yarn thickness relative to the reference yarn thickness. 6. A yarn monitoring device according to any of the claims from 1 to 4, characterized in that the correction section is configured to perform the first correction based on a correction quantity obtained by adding a first predefined fixed value defined in advance for each first period at an initial adjustment value defined before starting the movement of the yarn, and performing the second correction based on a correction quantity obtained by subtracting a second predetermined fixed value defined in advance for each second period from the value initial adjustment. 7. A yarn monitoring device according to any of the claims from 1 to 6, characterized in that the first correction is performed when a yarn thickness in a temporal instant of termination of a first current period confirmed in the first confirmation process is increased by a predetermined amount with respect to a yarn thickness in a temporal instant of termination of a first preceding period, and the second correction is performed when a yarn thickness of a second current period confirmed in the second confirmation process is continuously reduced . 8. A yarn monitoring device according to any of the claims from 1 to 7, characterized in that the correction section is configured to calculate an average of yarn thicknesses in a predetermined length or a predetermined previous time, and perform the first correction to correct the yarn thickness when the average of the yarn thicknesses in the time instant of termination of the first current period satisfies the predetermined increase condition. 9. A yarn winding machine (1) characterized by comprising: a winding section (26) able to wind a yarn to form a cone; a yarn thickness detection section (50) adapted to detect a yarn thickness of a moving yarn; and a correction section (62) adapted to correct the yarn thickness, wherein the correction section is configured to perform a first confirmation process comprising a step of confirming the yarn thickness detected by the yarn thickness detection section, and performing a first correction comprising a step of correcting the yarn thickness when the yarn thickness confirmed in the first confirmation process satisfies a predetermined increase condition, in a first predetermined period of time or length covered by the yarn, and performing a second confirmation process comprising a step of confirming the thickness of yarn detected by the yarn thickness detection section, and performing a second correction comprising a step of correcting the yarn thickness when the yarn thickness confirmed in the second confirmation process satisfies a condition of a predetermined reduction, in a second predetermined period of time or of length covered by the yarn, said second predetermined period being different from said first predetermined period. 10. Automatic winder (1) acting as a yarn winding machine according to claim 9, the automatic winder characterized by comprising: a section for detecting the length of movement of the yarn (61) suitable for detecting a length of movement of the yarn which it is a length that the yarn has traversed, wherein the winding section is configured to wind the yarn while at the same time varying a winding speed, and the correction section is configured for, based on the length of movement of the yarn detected by the detection section of the yarn movement length, perform the first confirmation process and determine whether the yarn thickness confirmed in the first confirmation process satisfies the predetermined increase condition each time the yarn travels through a first predetermined length, and execute the second confirmation process and determine if the yarn thickness confirmed in the sec However, a confirmation process satisfies the predetermined reduction condition each time the yarn travels through a second predetermined length.